Working from a dataset of 118 billion messages running from the start of 2009 to the end of 2019, we identify and explore the relative daily use of over 150 languages on Twitter. We find that eight languages comprise 80% of all tweets, with English, Japanese, Spanish, and Portuguese being the most dominant. To quantify each language's level of being a Twitter `echo chamber' over time, we compute the `contagion ratio': the balance of retweets to organic messages. We find that for the most common languages on Twitter there is a growing tendency, though not universal, to retweet rather than share new content. By the end of 2019, the contagion ratios for half of the top 30 languages, including English and Spanish, had reached above 1---the naive contagion threshold. In 2019, the top 5 languages with the highest average daily ratios were, in order, Thai (7.3), Hindi, Tamil, Urdu, and Catalan, while the bottom 5 were Russian, Swedish, Esperanto, Cebuano, and Finnish (0.26). Further, we show that over time, the contagion ratios for most common languages are growing more strongly than those of rare languages.

本研究以 2009 年至 2019 年期间推特上超过 150 种语言的每日使用率为基础，发现英语、日语、西班牙语和葡萄牙语等八种语言占推特所有推文的 80%；计算每种语言的社交传播指数，发现推特上普遍存在转发比原创推文更受欢迎的趋势，其中包括英语和西班牙语，而其他一些语言，如泰语、印地语、泰米尔语、乌尔都语和加泰罗尼亚语的传播指数较高。同时，我们表明，与稀有语言相比，常见语言的传染率更强。

社交媒体的不断扩张：测量2009-2020年Twitter上150多种语言的时间和社交传染动态